Drill-grinding machine



July 21, 1925. 1,547,032

G. w. CRANE DRILL GRINDING MACHINE Filed Aug. 1925 4 Sheets-Sheet l wumtoz a: 11 rwne Gnome/go JulyZl, 1925.

G. w. CRANE DRILL GRINDING MACHINE Filed Aug. 1923 4 Sheets sheet 2 July 21, 1925. 1,547,032

G. W. CRANE DRILL GRINDING MACHINE Filed Aug. 2 1923 4 Sheets-Sheet 5 f1m2:1

.245 25 IRIS-2E.

July 21, 1925. 1,547,032

G. W. CRANE DRILL GRINDING MACHINE Filed Aug. 2 1923 4 Sheets-Sheet 4 Wilma Patented July 21, 19259 ten sr GEORGE W. CRANE, OF NEW ORLEANS, LOUISIANA.

DRILL-GRINDING MACHINE.

Application filed August 24, 1923. Serial No. 659,225.

To all whom it may concern:

Be it known that I, GEORGE 1N. CRANE, a citizen of the United States, residing at New Orleans, in the parish of Orleans and State of Louisiana, have invented certain new and useful Improvements in Drill- Grinding Machines; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This application relates to drill grinding mechanisms for twist drills and has refer ence inoreparticularly to certain subject matter disclosed in slightly different form,

in my U. S. application, Serial No. 573,2?8, filed July 7th, 1922, in which application division was required. The present application is devoted to one of the inventions claimed in the prior application, certain changes and additions however, having been made.

The principal object of the invention is to provide a comparatively simple and easily operated drill grinder which will perform accurate work on different sized drills, and insure proper lip clearance.

A further object is to provide a grinder in which the drill being around, is held stationarily, and the grinding wheel may be moved in the direction of its own axis, and also pivotally moved, by one hand, leaving the other hand free for feeding the drill to the wheel.

Another object is to provide a grinder adjustable for different sized drills and provided with a drill caliper which automatically effects proper adjustment of the machine to grind any sized drill, when such drill is engaged with said caliper.

Other objects are to provide simple, yet effective forms of drill clamps, and to make unique provision for properly presenting the drills to the grinding wheel.

With the foregoing in view, the invention resides in the novel subject matter hereinafter described and claimed, tl1e,descrip-.

tion being supplemented by the accompany inc; drawlngs.

Figure 1 is a side elevation of a drill with my invention.

Figure IS a top plan V1BW.-.

grindin machine constructed in accordance Figures 3, 4 and 5 are vertical transverse sectional views as indicated by lines 38, i a and 5-5 respectively of Fig. 1.

Figure 6 is a detail horizontal sectional view, partly in elevation, showing more particularly the construction of the drill caliper.

Figure 7 is a sectional view on line 77 of F 6.

Figures 8 and 9 are detail elevations showinn; more particularly the stop means for limiting the pivotal movement of the grinding wheel.

Figure 10 is a transverse sectional view showing; a slightly different form of con struction.

Figures 11,12 and 13 are elevations illustrating different ways of driving the grinding wheel.

in Figs. 1 to 9 of the drawings, which illustrate the preferred form of my invention, the numeral 1 designates a horizontally elongated base preferably having lugs 2 throinqh which anchoring bolts may be passed to secure said base to a work-bench or other suitable support. Rising from one end of the base 1, is a standard 3 having a horizontal bearing 1 which extends longitudinally of the base 1. In this hearing, an arbor 5 is rotatably received, said arbor supporting an electric motor 6 whose shaft 7 is slidably mounted and is disposed oblique- 1y to the axis of the arbor. One end of the shaft 7 carries a grinding wheel 8 and a bellows seal 9 is preferably located between said wheel and the motor casing, to prevent the entrance of grit into the latter. while permitting the shaft 7 to be moved in the direction of its own axis. The other end of shaft 7 is provided with a knob 10 suitably swiveled thereon. a coiled compression spring 11 being; interposed between the motor casing and knob, to always retract the shaft 7 and wheel 8. Bv grasping the knob 10 in one hand, it will be seen that the shaft 7 may be axially sh fted a d t t all'parts supported by the arbor 5 ma b turned about the latter. these operat o s e ing necessary in properly .q'riudino: a dr l Mounted on the base 1, for adjustment to ward and from the standard 3, is a can-lane plate, 12 which may be locked in adjusted position by anycsuitable means 13.

second carriage plate 14 is mounted slidably upon the plate 12, for adjustment transversely of the base 1, on a line parallel to the direction normally taken by the shaft 7 (see Fig. 2). Suitable means 15 is provided for locking the plate 14 in adjusted position.

Rising from the plate 14, is a post 16 which carries a drill-holder, preferably of the construction shown. A longitudinal arm 1'? is secured at one end to the post 16, as indicated at 18, in such a manner that said arm may be swung to dinerent inclinations, graduations 19 being preferably provided for use in setting this arm, as it is instrumental in obtaining proper lip clearance on the drill being ground. A rigid drillsupporting arm 20 extends laterally from the anchored end of the arm 17 and is provided at its outer end with a stationary drill-engaging jaw 20 which is preferably of the L -shape disclosed in Fig. I have shown a lug 21 depending from the arm 20 and to this lug, an arm 22 is pivoted, said arm passing upwardly through a slot 23 in the arm 20 and having movable drillengaging jaw 24 on its upper end. To force the jaw 24 yieldably toward the drill, I provide a spring arm 25 which preferably passes through a yoke 26 on said This arm 25 is anchored to the arm 20 in any suitable manner and passes through the slot 23 and in order that the jaw 24 may be held in retracted position when desired, I pro vide a shoulder 27 at one end of said slot, with which the arm 25 may be engaged.

Spaced from the arm 20 and extending laterally from the arm 17, is an additional drill-supporting arm 28 which is adjustable along said arm 17, by means of a suitable clamp 29, said arm 28 being provided with means 30 for holding the drill, said means being similar to that above described, as shown most clearly in Fig. 4.

Between the arm 28 and the free end of the arm 17, is another lateral arm 31 adjustable along the arm 17, by means of an appropriate clamp 32, said arm 31 being provided with a suitable device 33 for feeding the drill being ground, to the wheel 8. E2;-

tending from the arm 31, I have shown a.

pin 34 which co-operates with a guide clamp 85 which is adapted to be clamped upon small drills, as shown in Fig. 2, to properly present the latter to the grinding wheel. For propertly setting this clamp upon the drill, I provide a setting device designated in a general way by the character 36, but its construction will not be described, as the present application is devoted to drill grinding mechanism.

Before proceeding further, it may be well to point out that the drill holder has its axis, that is the axis defined by the drill being held, disposed. obliquely of the grind ing wheel axis and preferably in substantial alinement with the axis of the arbor 5, although slight deviation from this last named axial alinement, is necessary to obtain proper lip clearance on the drill.

lVhen grinding different sized drills, it is necessary that relative adjustment must be made between the grinding wheel 8 and the drill holder, for which purpose, the carriage plate 14 is adjusted along the carriage plate 12. l have made novel provision, including a drill caliper, for automatically ei'l' ecting the proper adjustment of the drill holder with respect to the grinding wheel, according to the size of the drill engaged with the caliper. Thus, by first en gaging a drill to be ground with the caliper, in the present disclosure, the carriage plate 14 and parts carried thereby, are adjusted to a proper position along the carriage plate 12, and they are then clamped by the nut or the like 15. Then, the drill is stationarily held in the drill holder, being engaged with the jaws of the arms 20 and 2S, and proper presentation of the drill to the grinding wheel is effected, either by co-action of the previously applied clamp 35 with the pin or by projection of a slide 3? which is carried by a lateral extension 38 of the jaw 20, or otherwise suitably mounted, said slide being projectable into one of the grooves of the drill. By now adjusting the feed device 33, the drill may be moved into contact with the grinding wheel 8 and the latter may be pivotally'swung about the arbor 5, and shifted along its own axis, by means of the knob 10, thus effectively grinding half of the drill point. Then, turning of the drill a half revolution, will permit the other half of its point to be similarly ground.

In the preferred form of construction, the drill caliper takes the form illustrated most clearly in Figs. 6 and 7. One end of the carriage plate 14 is formed with a guideway 89 in which a slidable metal plate 40 is mounted, said. plate having a cam 41 hearing against a stud or the like 42 which rises from the plate 12, so that outward movement of the slide plate 40 against the action of its retracting spring 43, will cause the cam and stud to co-operate in sliding the plate 14 and the drill holder carried thereby, along the plate 12, it being of course understood that the locking means 15 has been previously released. The outer end of the slide plate 40 is provided with a lateral shoulder 44 which is co-operable with one edge of the plate 14 in forming a caliper for any drill to be ground. As shown by dotted lines in Fig. (i, the plate 40 is pulled outwardly, and the drill is positioned betweeen i'he shoulder 44 and the plate 14. Outward movement of the plate 40 to the extent necessary for positioning the drill in this manner, automatically causes the cam 41 to adjust the plate 14 and the drill holder to the proper position for receiving the same drill, during the grinding operation. The locking means 15 is then tightened, the drill is positioned in the holder, and the grinding operation is performed.

In Fig. 11, I have shown a bearing l? supporting an arbor 5 corresponding to the arbor 5, said arbor carrying an oblique bearing 6 for the grinding wheel shaft 7 which is slidable therethrough and may be moved in the manner above described. For driving the shaft 7 in this modified form of construction, l have shown a belt 45 and pulleys 46.

In Fig. l2, a gear casing 47 connects the grinding shaft bearing 6' with the arbor 5 a shaft 1:8 passes rotatably through this arher and gears 49 are located in the casing 47 for driving the grinding wheel shaft 7 from said shaft 48. y

In Fig. 13. the construction shown is very similar to that of Fig. 11, but a flexible shaft 48 is employed to drive the grinding wheel shaft 7. In this figure, lO iindicates a suitable handle for axially moving the shaft 7 and for swinging it about the arbor.

Fig. 10 discloses a modified manner of adjustably mounting an arm 1T, corre sponding to the arm 17. This arm is provided with a tubular trunnion KO-passing through an opening in the upper end of the post l6 corresponding to the post 16, a lever nut or the like 51, being threaded on said extension 50 to hold thearm 17 in adjusted position. Within the extension 50, l have shown a plunger 52, projectable under the influence of a spring 53 to hold the drill being ground. A. stem 54L extends from the plunger 52 and is provided with an operating sleeve 55 which is threaded on the extension 50 for the purpose of retracting the plunger 52 as desired. This figure (.10) also illustrates a slightly different mounting for a slide 37 similar to the slide 37.

By constructing the grinding machine in, or substantially in, the manner shown and described, it will be highly eificient and desirable for grinding numerous sizes of drills and giving them the proper lip clearance. Excellent results have been obtained from the general structure disclosed, and it is therefore preferably followed, but within the scope of the invention as claimed. nu merous modifications may be made.

I claim:

1. A twist drill grinder comprising holder for non-rotatably mounting a drill. a grinding wheel. whose axis is oblique to and substantially intersects the axis of said holder, and means pivotally mounting said wheel for movement over the end of the drill about an axis oblique to the wheel axis, said pivotal axis of the wheel mmlnting means being substantially in line with the axis of the drill holder but slightly oblique thereto.

a. twist drill grinder comprising a holder for non-roiatably mounting a drill, a gr rding wheel whose axis is oblique to and .istantially intersects the axis of said holder, means pivot-ally mounting said wheel for movement over the end of the drill about an axis oblique to the w axis, and a single handle for axially shi .ting the wheel across the end of the drill and for moving said wheel. about its pivotal axis.

3. A. twist drill grinder comprising a holder for non-rotatably mounting a drill, a grinding Wheel whose axis is oblique to and substantially intersects the of said holder, means pivotally mounting said wheel for movement over the end of the drill on an axis oblique to the wheel axis, and means for changing the angular relation of t ie of said drill holder with respect to the pivotal axis of the wheel mounting means to obtain diiferent clearances on the drills ground.

4:. A twist drill grinder comprising a holder for stationarily and non-rotatably mounting a drill, a grinding wheel whose axis is oblique to and substantially inter-.

sects the axis of said holder, means mounting said. wheel for movement oi'erthe end of the drill about an axis oblique to the wheel axis, and means for adjusting said drill holder in a direction oblique to its length but substantially parallel. to the direction normally taken by the wheel axis.

5. A twist drill grinder comprising a support provided with a horizontal bearing, a horizontal arbor rotatable in said bearing, a grinding wheel having a shaft supported rotatably by said arbor, said shaft extending obliquely of the arbor, and a drill holder for non-rotatably mounting a drill in operative relation with said grinding wheel.

6. A twist drill grinder comprising a support provided with a horizontal bearing, a horizontal arbor rotatable in said bearing.

, a grinding wheel having a shaft supported rotatably and slidably by said arbor, said shaft extending obliquely of the arbor, a single handle for axially sliding said shaft and turning said arbor in said bearing, and a drill holder for non-rotatably mounting a drill in operative relation with said wheel.

7. A twist drill grinder comprising an elongated base, a horizontal bearing mounted on said base and disposed longitudinally thereof, an arbor rotatable freely in said bearing and disposed longitudinally of the base, a grinding wheel having a shaft rotatably supported by said arbor, said shaft extending obliquely of the arbor, a track extending obliquely across the upper side of said base substantially parallel with the axis of the grinding wheel shaft, a slide adjustabl along said track and having an upstanding post, a rigid substantially horizontal arm secured at one end to said post and extending longitudinally of the base therefrom, and drill-holding and adjusting means carried by said arm for non-rotatabl holding a drill and adjusting it toward and from the edge of the grinding wheel.

8. A structure as specified in claim 7 said rigid arm being pivoted to said post on a horizontal axis extending transversely of the base, permitting said arm to be swung upwardly and downwardly to different positions.

9. A structure as specified in claim 4L; said adjusting means for said drill holder comprising a slide member on which the holder is carried, a track member on which said slide is movable, an abutment on one of said members, a movable cam on the other member engaging said abutment for shitting the slide member on the track member when operated, and means for operating said cam comprising a drill caliper adapted to move said cam proportionately to the size of the drill being calipered.

10. A structure as specified in claim 4:; said adjusting means for said drill holder comprising a slide member on which the holder mounted, a track member along which said slide member is movable, an abutment on one member, a slidable cam carried by the other member and engaging said abutment for adjusting the slide member along the track member when operated, an operating shank extending from said cam in the direction of its movement, and a shoulder on said shank co-operable with a portion of one of the aforesaid members to form a drill caliper.

11. A twist drill grinder comprising a grinding wheel; a drill holder associated with said wheel and movable carrying member on which said holder is mounted for adjustment with respect to the grinding wheel, according to the size of the drill to be ground, a stationary member on which said carrying member is movably mounted, and a slidable drill caliper carried by one of said members and having a cam engaging a part of the other member to effect proper adjustment of said carrying member for grinding any drill engaged with the caliper.

12. A twist drill grinder comprising a movably mounted grinding wheel, a drill holder for stationarily holding a drill to be ground, and a guide member separate from the drill holder and adapted to be clamped temporarily on the drill during the grind ing operation, said holder having a portion co-operable with said guide member to properly present the drill point to the grinding wheel.

13. A drill clamp for grinding machines comprising a drill support having a stationary drill-engaging and a slot adjacent said jaw, means for holding the drill against said stationary jaw, comprising a spring arm extending through said slot and movable under its own resiliency toward said jaw, and a shoulder at one side of said slot for holding said spring arm retracted when desired.

In testimony whereof I have hereunto a'liixed my signature.

GEORGE W. CRANE. 

